PDA

View Full Version : Negative Versus Paper Contrast in Zone System B&W Calibrations



neil poulsen
3-Mar-2016, 10:08
I've completed calibrations for Ilford HP5 developed in D76 a little differently than I've previously conducted these tests.

Ultimately, whether a conscious decision or not, one makes a choice about the paper contrast that will be used during the calibration process. Testing for film speed, of course, is independent of the choice of paper contrast. However, after the film speed has been found (usually about ASA200 for HP5), I will determine my enlarger and timer settings to print just at maximum black on the paper of choice, and then I will print a number of negative densities at these settings to decide which negative density gives me a Zone VIII that I like. (Some will use Zone VII, or other zones, for this comparison.) Once I know this density, I can establish "N" (normal development), and subsequently, all the remaining developments. (N-1, N+1, N-2, and N+2.)

Examining the choice of paper contrast a little more closely, if one chooses a higher paper contrast, a Zone VIII will not be quite as dense on the negative, and the different developments (N, etc.) won't require as much contrast to achieve that density. So overall, negatives won't be quite as contrasty. (Correct or not, this is the logic from which I'm operating.)

On the other hand, if a paper is chosen with less contrast, one will need to extend the times of the different developments (N, etc.), to achieve the desired Zone VIII density. So overall, negatives will be more contrasty.

To the question that I'm exploring and posing in this thread, which is better? Should one select a paper with less contrast, and thereby end up with higher contrast negatives? Or, should one do the converse and select a higher contrast paper and end up with lower contrast negatives?

As to what's different in my most recent calibrations, in the past, I've picked Ilford Gallery grade 3 contrast paper on which to base my calibrations. Thereafter, all my printing would be on VC papers, usually Ilford warmtone glossy FB. After making this choice, I've typically achieved results that I like quite a lot. (Note also that I used D76 as my developer this time 'round, whereas in the past, I've used Ilford's ID11. My understanding is that ID11 is Ilford's version of Kodak's D76.)

But in a previous thread long ago, LF Forum members admonished me for this, suggesting instead that I should base my calibrations on the paper on which I will print. Fair enough. I now print B&W using a Beseler 45s color head mounted on my enlarger, so I chose Ilford Warmtone glossy FB as my paper printed without any color filtration (neither yellow nor magenta) on the 45s. (I've read that VC papers printed without color filtration is a good approximation of a normal, grade "2" contrast.) In time, I'll see whether I like this choice better, or not.

Let me provide a little explanation regarding previously basing my calibrations on Gallery 3 papers. If one uses a VC paper during calibrations, there's always the question, at what filtration? In this regard, I've always felt like I had my feet firmly planted in the clouds in trying to make this decision. So, I chose a graded paper, and to ease contrast on the negatives, and for shorter development times, I chose grade "3' versus grade "2". Plus, I've read that a Gallery 3 is only about a half-grade higher in contrast than what would be considered "normal," Grade 2 contrast.

Defending a little my previous practice of using a different paper for calibrations than that used for printing, my logic goes as follows. When Ansel Adams conducted his earlier calibrations, he probably had no idea what papers might or might not be still in production years later on which to print earlier negatives. So, why should it matter, as long as he liked the results he was getting? Of course, with years of experience, I assume that he pretty much knew the negative densities he would need for Zone VII or VIII exposures. (I guess this is what I'm still exploring.)

Please note that I don't spend all my time testing. I will use a set of development times for years before next engaging in a new set of calibrations.

So back to the question that's being posed? Which is better: a little higher paper contrast that results in overall lower negative contrast; or, "normal" contrast paper grades that result in higher overall negative contrast?

Ken Lee
3-Mar-2016, 10:20
With Large Format film and normal-sized prints, grain is less of an issue, but remember that with ordinary developers and ordinary agitation, greater development increases grain. At the same time, shortened development reduces film speed.

I haven't made many darkroom prints in a while, but given the trade-off, I'd stick with the middle path: negatives and paper of moderate contrast. This should handle the majority of subjects.

For cases where extreme expansion and contraction are required - or when using special developers or agitation methods - other approaches may be required.

As an amateur I find it easier to select subjects that are already well within the comfort range of the equipment: it's a more pleasant experience all the way along.

Drew Wiley
3-Mar-2016, 10:25
Why do you make things so complicated? There a very few graded papers even left. If you negs work fine for your preferred Ilfobrom Galerie 3, they'll be fine
for most VC papers too, especially Ilford ones. Even "Zones" are a plastic concept which differs from film to film, depending on the specific characteristic curve.
Change any variable, and all this need to be re-calibrated. I don't bother. But that doesn't mean I'm sloppy. Having a versatile neg with some flexibility is a lot
smarter than making an air-tight religion out of the Zone System. Lately I've gone back to some of my early LF negs and have reprinted them using modern VC
papers. Negs which were once hell to print are extremely easy now. But back then, as now, I consider Grade 3 my base point.

bob carnie
3-Mar-2016, 10:27
Not sure if this helps Neil- but when calibrating digital fibres we use a higher than normal paper- I think it is Galerie grade 4 with an extended red sensitivity. Once the 21 step wedge is calibrated all file print normal.

When I first started this we were using Agfa Classic which was a VC paper so the calibration stage would be made for a lower grade starting point.

I guess my point would be that both works in Digital , I do not see why the same would apply in your situation

Drew Wiley
3-Mar-2016, 10:45
Does Gr 4 Galerie still even exist, Bob?

bob carnie
3-Mar-2016, 11:28
I believe this is the source emulsion for my digital paper.

Does Gr 4 Galerie still even exist, Bob?

Peter De Smidt
3-Mar-2016, 11:35
True paper grades can be determined by printing a step wedge. If you have access to the book Way Beyond Monochrome, Ralph and Chris outline the method for figuring this out. This can be useful when printing on VC papers with a color head. Personally, I used Paul Butzi's method for constant exposure (and Zone VIII density) on VC paper while varying contrast through changes in filtration. This was very useful. Use exposure to get a good highlight level in the print, and then use filteration (and the same exposure) to give the overall contrast needed.

ic-racer
3-Mar-2016, 12:53
So back to the question that's being posed? Which is better: a little higher paper contrast that results in overall lower negative contrast; or, "normal" contrast paper grades that result in higher overall negative contrast?

Steve Benskin once posted a tone reproduction curve with #3 paper that had a straighter line than the other grades. The difference between that and grade #2 was small.

RSalles
3-Mar-2016, 13:50
Neil,

Paper and film contrast being 2 variables I suggest you keep one constant. I don't want to bring you back to the basics of the ZS but don't forget the scene itself,: that's where contrast comes from.

What's my approach - which can or not work for your use:

I try keep the paper grade as a fixed grade #2 as starting point, working with negative contrast with development on the range -3 till +3 when grain and film speed permits me those extremes.
Example: In front of a scene with low contrast where shadow detail falls on the range of Z II - Z,IV and highlights falls on Z VI I'll keep film speed constant as what came on film speed testis and expand the contrast with development until Z VI rises till ZVIII (N+2) with #2 paper contrast in mind - as I use Ilford filters and (VC papers) which goes from #00 to #5 in halves.

About paper contrast I have to say that VC is sort of new decision for me, I always used fixed grade and fiber base papers.
Changes in the contrast of the paper for the final print is an artistic decision, but my first goal is to have "everything there" in the negative until entering in the darkroom to print.
Sometimes I don't have "everything there" and it's **ing annoying, as it imposes restrictions exactly where I need more room to work, the "final look",

So, to answer to your question "which is better" IMO to work with negative contrast targeting #2 paper - in my case and #3 in yours - grade in mind, and decide later for each particular print to add or lower from that fixed or constant,


HTH,

Renato

Drew Wiley
3-Mar-2016, 14:38
Every damn species of paper, with any potential change in either developer per se, or length of development, throws all those neat little "constants" out the window, not to mention what toning does. I guess if you don't fiddle with any of that. But sooner or later the manufacturer will, or might just cease to exist.
And every scene presents its own challenges. Since this is a large format forum, sheet film at least lets you target specific development for any given shot;
but in principle, once roll film is involved, you have to make the whole roll squeeze into something or other - in other words, survival of the fittest, negative-wise, favors a versatile negative, capable of being printed more than one way. Silver-rich papers will themselves tolerate quite a range of development time relative to contrast; but that often is inverse to something related to final image color. Cooler tones on allegedly cool or neutral papers require relatively "complete" development. Just so many damn factors involved that are so complicated to quantify, but really easy to just do. But if you're in the business of selling how-to darkroom books or gadgets, you might favor doing things the hard way. Or maybe one just needs to work through their darkroom adolescence
of trying this n' that, the school of hard knocks, first. That was certainly the case with me. Yeah, I've got fancy toys. Lots of them. But they rarely come into
play in basic black and white printing.

neil poulsen
4-Mar-2016, 01:34
Neil,

Paper and film contrast being 2 variables I suggest you keep one constant. I don't want to bring you back to the basics of the ZS but don't forget the scene itself,: that's where contrast comes from.

What's my approach - which can or not work for your use:

I try keep the paper grade as a fixed grade #2 as starting point, working with negative contrast with development on the range -3 till +3 when grain and film speed permits me those extremes.
Example: In front of a scene with low contrast where shadow detail falls on the range of Z II - Z,IV and highlights falls on Z VI I'll keep film speed constant as what came on film speed testis and expand the contrast with development until Z VI rises till ZVIII (N+2) with #2 paper contrast in mind - as I use Ilford filters and (VC papers) which goes from #00 to #5 in halves.

About paper contrast I have to say that VC is sort of new decision for me, I always used fixed grade and fiber base papers.
Changes in the contrast of the paper for the final print is an artistic decision, but my first goal is to have "everything there" in the negative until entering in the darkroom to print.
Sometimes I don't have "everything there" and it's **ing annoying, as it imposes restrictions exactly where I need more room to work, the "final look",

So, to answer to your question "which is better" IMO to work with negative contrast targeting #2 paper - in my case and #3 in yours - grade in mind, and decide later for each particular print to add or lower from that fixed or constant,


HTH,

Renato

Of course, all of this goes back to the original scene, where one places the shadow in the desired location with exposure, and then develops to set the highlights in the desired area. I place the shadows using the traditional Zone III and develop to make my chosen highlight a Zone VIII.

But, if I'm going to attempt to make a highlight in the scene a Zone VIII, I also want to have determined for myself how much density Zone VIII should have.

The primary "single" variable that I've changed is the paper, which is Ilford warmtone glossy fb instead of Gallerie 3. I suppose that I've also changed the developer to D76. But given the similarities between D76 and ID 11, I don't see that as having much influence.

neil poulsen
4-Mar-2016, 01:38
Steve Benskin once posted a tone reproduction curve with #3 paper that had a straighter line than the other grades. The difference between that and grade #2 was small.

Interesting. Thanks for this reassurance.

I've seen Way Beyond Monochrome, and it looks like a really excellent book. It sounds like it has a sound approach for establishing my own contrast levels in whatever paper I'm using.